Pipeline Optimization Accounting for Transient Conditions: Exploring the Connections between System Configuration, Operation, and Surge Protection

The optimal design of a water distribution system under worst-case transient loadings is formulated as a two-step optimization problem. In the first step, particle swarm optimization is used to identify the set of critical nodes that will result in the worst case transient loading condition. In the second step, dual-objective optimization is used to determine the optimal pipe sizes that simultaneously minimize cost and the likelihood of damaging transient events, measured by a parameter called the surge damage potential factor. Nondominated sorting genetic algorithms are combined with transient analysis to produce a set of Pareto-optimal solutions in the search space of pipe cost and surge damage potential factor. The case study tested on the New York tunnel system confirmed that pipe size is a significant factor in controlling transient response. It is concluded that transient consideration in the design phase, in conjunction with conventional least-cost pipe size optimization, will help water utilities achieve a high degree of hydraulic integrity and reliability and extend the life of their distribution systems. Enhancement of water distribution system planning and management is a principal benefit of the proposed methodology.